This has been the summer of "intelligent design." In August, President Bush endorsed this revamped version of creationism, and this week a Pew Forum poll found that fewer than half of Americans accept Darwin's theory of evolution. This widespread rejection of seemingly established truths has shocked many observers. After all, didn't the Scopes trial resolve this 80 years ago?

The anniversary of the "Monkey Trial" provides an occasion to remember that it didn't really settle what we assume it settled. Popular memory of the trial, reinforced by the 1960 movie Inherit the Wind, made it seem that evolution was triumphant and fundamentalism vanquished, but in fact the result was much more ambiguous. Anti-Darwinism didn't die in Dayton, Tenn., in July 1925—it just retreated temporarily from the national scene, to which it has now returned.

Like the 1960s, the 1920s witnessed a series of culture wars. After decades in which liberalism and science had gained popular acceptance, a backlash arrived in the '20s. A revived Ku Klux Klan swelled to 5 million members. Feminism, having secured women's suffrage, stalled. The 18th Amendment, passed in 1919, prohibited the sale of alcohol. Congress restricted the immigration of peoples deemed undesirable.

Evolution marked another front in these fights. Although Darwin's theories had met fierce resistance when first proposed in 1859, in time they secured general approval. Even many Christian leaders, once hostile to evolution, endorsed the theory—one of several trends that split many Protestant denominations into modern (or liberal) and fundamentalist camps. "By the time of World War I," wrote the historian William Leuchtenberg, "an attack on Darwin seemed as unlikely as an attack on Copernicus."

But attack the fundamentalists did. Advocating a literal reading of the book of Genesis, they attained political power in many states, particularly in the rural South and Great Plains. In Tennessee, Oklahoma, and Mississippi, they passed laws forbidding the teaching of evolution.